Tuner



'8. A. SCHWARZ ET AL April 11, 1944.

TUNER Filed Feb. 4, 1942 2 Sheets-Sheet l My w a. a

April 4- B. A. scHwARz ETAL. 2,345,399

TUNER Filed Feb. 4, 1942 2 Sheets-Sheet 2 a mam 8,, zldgy 4amw I GttomegPatented Apr. 11, 1944 TUNER Bertram A. Schwarz and Ludwig J. Fichter,Kokom0, Ind., assignors to General Motors Corporation, Detroit, Mich., acorporation of Delaware Application February 4, 1942, Serial No. 429,442

8 Claims.

This invention relates to indexing means and more specifically toindexing mean associated with tuning apparatus for radio receivers. Ithas become quite common to construct radio receivers wherein by merelypressing upon either a pivoted or slidable member and actuating it overa short distance it is possible to tune a radio receiver to certainpredetermined set stations in addition to the usual manual tuning knob.There are always a few radio stations to which the owner of a receiverordinarily listens. These are of course generally the transmitterswithin a rather limited radius of the location in which the receiver isoperated and these may be set up on automatic tuning apparatus.

It is therefore an object of our invention to provide actuatable meansfor automatically indexing the tuning mechanism of a radio receiver.

It is a further object of our invention to provide mechanism which maybe easily reset to other stations as desired.

It is a still further object of our invention to provide tuning meanswhich is rugged and dependable and will not jar off station.

With these and other objects in view, which will become apparent as. thespecification proceeds, our invention will be best understood byreference to the following specification and claims and theillustrations in the accompanying drawings, in which:

Figure 1 is a front elevation of a tuning mechanism according to ourinvention;

Figure 2 i an enlarged sectional view taken on line 2-2 of Figure 1;

Figure 3 is a top plan view of the tuner of our invention;

Figure 4 is an end elevation of our invention;

Figure 5 is a sectional view taken on line 55 of Figur 6;

Figure 6 is an enlarged sectional view taken on line 6-6 of Figure 4;and

Figure 7 is a sectional view taken on line 1-1 of Figure 3.

Referring now more specifically to the drawings, there is shown inFigure 1 the front plate 2 of a tuning mechanism through which project avolume control member 4 and a manual tuning knob 6 at the left'and righthand extremities respectively and between which project a number ofhorizontally slidable push buttons 8 for so-called automatic tuning. Thetuning mechanism is supported in a casing 10 which is in the form of arectangular shallow box having two side plates l2 and' l4. Supportedbetween these side plates is a treadle bar assembly composed of twohorizontal rods 16 and [8 which are secured at their ends to plates 20and 22. Plate 2|] carries a substantially cylindrical boss 24 having acentral depression within which is carried a small ball bearing pivot 26whose positionjis adjustable by a threaded member 28 in which it iscarried which is supported on the side plate l2 and locked in positionby a lock nut 30. The opposite plate 22 has secured rigidly thereto ashort shaft 32 which extends through the side plate [4 and carries meansthereon which may be manually operated to turn'the treadle assembly andwill later be described.

The outer end of both plates 20 and 22 has pivoted thereto a lever arm34 and 36 respectively, the outer ends of each being pivotally connectedto a transverse rod 38. j This rod has a length greater than thedistance between the two side plates [2 and I4 and the opposite endsextend through longitudinal slots 40 so that this rod may be slidlongitudinally of the frame. Thus a the treadle bar rotates, the levers34-36 cause the rod 38 to be moved longitudinally of the frame.Pivotally secured to the rod 38 at various axial points are a pluralityof lugs 42to which are threadedly attached, in this instance comminutedcore members 44,which cooperate with associated coils not shown per sewhich are located within shield cans 41. Thus, as the rod 38 moves, itin turncauses the tuning means, in this instance and for illustrativepurposes only the comminuted cores, to tune the radio receiver. l i

The mechanism for adjusting the treadle bar assembly to various setpositions will now be described and comprises a series of longitudinallyextending shafts 46 which have the inner end extending through anopening 48 in a vertical portion 50 of the casing I 0. The forwardportion of each is carried by a second vertical portion 52. Anintermediate portion of the shaft 46 carries a plurality of threadedportions 54 and 58 which are adjacent each other and are threaded inopposite directions. Adjacent the inner end of the threads 58 there ismounted a washer 60 which acts as a stop for oneend of a. helical spring62 mounted on the rods, the opposite end of which bears against theinner surface of the vertical portion 50 0f the frame. This tends tonaintain a bias outwardly on each of the shafts 4 V The outer end of thethreads 54 bears against a washer 64 which in turn bears against a plate66 of sound insulating material on theinner surface of the member 52'to'thus cause a stop in shaft. The outer end of the cylindrical member.

is knurled as at I8 and over this outer end there is adapted to be slida hollow manual push button knob 8 which is maintained thereon :byfriction and also by some spring pressure from the locking spring 10.

Carried on the threaded portion 54 of the shaft is a traveling nut 82which extends on both sides of the shaft and has secured thereto one endof a pin 84. It also has an opening 86 therein to slidably support theend of a second pin member 86'. "Supported, on the other threadedportion 58 is a second traveling nut'SIl which slidably supports "theopposite end of'the pin 84 and rigidly supports "an intermediate'portionof thepin 86. Each of these traveling nut assemblies has a projection"92which "extends down into a Slot 94 in the.bottom of the casing wherebythese travel: ing nuts are preventedfrom rotating on the shaft butmaymove axially 'thereaiong.

rhepmsai and'86' are 'so located as. to lie 'in aligmiien't with"th ftreadle bars l6 and I8, the axis of the shaft '46 assing between the twotreadle bars. It will thus be evident that as the shaft '46 is rotatedabout its own axis, the traveling nuts will move eithertoward or awayfrom eachotherfdependingupon'the direction of rotation,fand that inv sodoing the pins 84 and 86 will move with respect to each other so thatthey are either in alignment or one or the other is ahead and'th'uswhen'the shafts 46 are depressed by manual force applied to the end ofthe knob 8, they 'will setthe treadle bar-in a position dependent uponthe position of the ends 0f the pins. This .will in turn of coursesetthe tuning mechanism to a similar position. .Once the pins havebeen-adjusted to the desired position, however, each reciprocaloperation of a given knob 8 will always bring the treadle bar and tuninmechanism back to the same relative position and thus provide automatictuning to the same radio transmitting station. In the device shown, fivestations may thus-be set up, though any number may be provided. It is ofcourse'necessary to provide also anemia means for setting the receiverat an intermediate, pint between the two limits of operation and in thiscase this is provided by a rotatable shaft -96 which is driven by themanual'kn'ob- 6 and drives through a flexible cable 98 a" 'worm wheelI00. This worm wheel 'I'Illl meshes with a gear I02 mounted on a collarI04 loosely mounted onthe stub shaft 32. This worm drive is irreversibleand must be'disconnected when the automatic buttons are depressed .andtherefore the collar and gear carry aclutch portion I'BB'which isadapted to engage a friction disc I08 which is 'rigidly connected to theshaft 32 by a set screw H 0.

The collar Ill4'ha's in its outer surface a groove H2 in which'lies aportion of 'a lever H4 which is pivoted to the frame at H6. Acompression spring H8 bears against'the frame and one end of thecollariI'M and tends to force it axially to maintain the Jclutch partsin engagement. The

spring may be overcome however by movement of the lever I I4 which pullsthe clutch parts away from each other and disengages the clutch. Theouter end of the lever I I4 is connected to one end of an L-shaped leverH6 by a resilient connection such as In, the main portion of the leverH6 lying parallel to the rear member of the casing. It is mounted bymeans 'of short studs H8 which :extend. through slots I20 in itssurface, thus providing means whereby it may slide .-.transversely of thcasing or parallel to the axis .;of the treadle bars.

There are in the surface of this lever a plurality of -angularly;upturned portions I22 which overlie.the ends :of the reciprocatingshafts 46 whichare drawn to a conical tip such as I24, thus forming ac-amming surface whereby with inward reciprocation of the shafts 46, thetip of the shaft I24 cams its associated projection I22-tocause thelever H6 to move toward the left of the tuning mechanism looking. at thesame from the front,thus moving, the lever II'4 to the left about itspivot and disengaging the clutch so that the treadle bar assemmy andshaft. 32 may move without any engagementwith the irreversible worm andgear assembly of the manual drive when the automatic buttons aredepressed. In order, however, to setup new station's for the pushbuttons which are'norm'ally operated to bring in eommomy used station's,it is necessary to provide a locking-in means so that the shaft 46 whichis being reset to a new position of index maybe locked in during, theperiod that the operator wishes to rotate the shaft for this purpose andhe will not have to hold in and turn at the same time. Normally, ofcourse, upon merely depressing the shaft as soon asthe two pins 8-4 and86' have forced the treadle bar around to a bottoming position, theshaft 46 is immediately returned to its outer inoperative position bythe coil spring 62. However, for'resetting purposes we provide atransverse latch bar I 24 which extends across the front of the frameandlies just within the front panel. ,This bar is roughly of U-shape. andis pivoted atfits extremities I25 in the side plates I2 and I4 of theframe. It has a rear section which is stamped upwardly, asbest shown inFigure 2,'tof 'orm a raised portion I28 and the forward portion thereofis tape'red upwardly as shown. at .I'30 so that when any one of the.push buttons is depressed, the transverse bar I24 'is lifted dueto thecamming action of the surface I30 with the enlarged portion 'of themember '68 on thev shaft46, As the portion. proceeds to the rear,however, it passes under the 'bar I24. If the manual knob 'B ,isinplace, no locking action occurs as the upper .surface of 8 merely holdsthe locking barjup and the shaft is forced back out as soon asmanualpressure is removed, but when the manual knob '8 is removed, thepart I6 8.wi1l pass throughunder the bar and the front'fa'ce of theenlarged portion of the member 68 at I32 rides backuntil the transversebar I24 snaps down andlOcks this member 68, and-of course the shaft 46,in its innermost position. The vertical bias on this latch bar isprovided by two helical springs I34 which force the upperfaceo'f thelever downwardly and are biased against two lugs onthe frame.

When the .shaft 46being reset 'is locked thus in its inner position, thesame may be rotated and in so doing of "course thetravelingfnuts 82 and9ll are moved back and forth on, the shaft to adjust the pins 84 and 86'which are now in contact obvious that when one of the automatic $326,399wi h the treadle bar until the desired stati n bring the tuningmechanism to any desired position. To tune the receiver to any otherstation than those set up on the push buttons, it is of course onlynecessary to manually rotate the manual knob B which is connected to thetuner at all times, except during actuation oflone of the pushbuttons. If I In'j'order to prevent the tuning mechanism from drifting 01f stationdue to vibration, it will be push buttons has been actuat'e'd't'o bringthe device 'to a station, as soon as it is released the clutch memberwill again engage the manual drive and the irreversible worm'gear willact as a locking means to maintain the t g mechanism in its adjustedposition.

We claim:

1. In tuning mechanism, means for tuning a radio receiver, pivoted meansextending a substantial distance on each side of its axis connected tothe tuning means to move the same, a plurality of spaced reciprocableand rotatable rods supported at right angles in at least one plane tothe pivoted means, each having threaded portions of opposite sign,blocks threaded on each of the portions, means to prevent the blocksfrom rotating, spaced abutments each of which is carried by both theblocks of each reciprocating rod which project toward and engage thepivoted means to turn the same upon reciprocation of the rod, wherebyrotation of one of the rods causes relative motion between the abutmentscarried thereby for adjustment.

2. In tuning mechanism, means for tuning a radio receiver, means formoving said tuning means to a plurality of predetermined positions, apivoted member for driving the moving means, a plurality of rotatableand reciprocable members movable at right angles to the axis of thepivoted member, adjustable members on each of the last mentioned memberson opposite sides thereof and projecting toward the pivoted memberadapted to engage and index the same whose position may be changed byrotation of the first named members, removably manually engageable meansto actuate each of the plurality of members separately and independentlymounted thereon, and locking means engageable with and adapted tomaintain any one of the members movable at right angles at one extremeof their travel only when the manually engageable means is removed butsimultaneously permit rotation for adjustment of the adjustable members.

3. In tuning mechanism, means for tuning aradio receiver, a pivotedmember having substantial surface area on both sides of its axis ofrotation, reciprocable and rotatable spaced rods mounted at right anglesto the pivoted member in at least one plane having oppositely threadedportions, traveling nut assemblies on each threaded portion, abutmentson each nut assembly projecting toward the pivoted member whereby as therods are rotated the relative position of the abutments will be changedand index the pivoted members to a different position upon reciprocationof the rod, manual means for directly rotating the pivoted member,removable manual knobs mounted on the extendingv end of each rod, andspring biased locking means engageable with saidrods and operative onlywhen the knob is removed to maintain the rod actuated in it innermostposition.

4. 'In tuning mechanism, means for tuning a radio receiver, a pivotedmember having substantial surface area on bothsides of its axis ofrotation, reciprocable and rotatable spaced rods mounted at right anglesto the pivoted memberhaving oppositely threaded portions, a pair ofspaced traveling nuts on each rod whereby as the rod is rotated the nutswill move relatively, a pair of axially extendingpins carried in bothnuts on opposite sides of each rod, said pins being alternately securedto the nuts so that relative motion between the nuts will alter thevertical alignmentof the pins, said pins extending toward andadapted toengage the pivoted member to index the tuning mechanism upon reciprocalmovement of each rod and adjustable to difierent positions by rotationof each rod.

5. In tuning mechanism, means for tuning a radio receiver, a pivotedmember having substantial surface area on both sides of its axis ofrotation, reciprocable and rotatable spaced rods mounted at right anglesto the pivoted member having oppositely threaded portions, a pair ofspaced traveling nuts on each rod whereby as the rod is rotated the nutswill move relatively, a pair of axially extending pins carried in bothnuts on opposite sides of each rod, said pins being alternately securedto the nuts so that relative motion between the nuts will alter thevertical alignment of the pins, said pins extending toward and adaptedto engage the pivoted member to index the tuning mechanism uponreciprocal movement of each rod and adjustable to difierent positions byrotation of each rod, removable manually engageable means mounted oneach rod end, and locking means to retain the rod in its innermostposition when the manually engageable means is removed but inoperativeto lock the rods when the manually engageable means is in position.

6. In tuning mechanism, means for tuning a radio receiver, a pivotedmember having substantial surface area on both sides of its axis ofrotation, reciprocable and rotatable spaced rods mounted at right anglesto the pivoted member having oppositely threaded portions, a pair ofspaced traveling nuts on each rodwhereby as the rod is rotated the nutswill move relatively, a pair of axially extending pins carried in bothnuts on opposite sides of each rod, said pins being alternately securedto the nuts so that relative motion between the nuts will alter thevertical alignment of the pins, said pins extending toward and adaptedto engage the pivoted member to index the tuning mechanism uponreciprocal movement of each rod and adjustable to diiferent positions byrotation of each rod, means for the pivoted member, clutch manual driveand the pivoted member and means actuated by the reciprocating movementof any rod to disengage the clutch means.

rods mounted at right angles to the pivoted member having oppositelythreaded portions, a pair of spaced traveling nuts on each rod wherebyas th'erod is rotated the nuts will move relatively, apair'of axiallyextending pins carried in both nuts on opposite sides of each rod,'saidpins being alternately secured to the nuts so that relative motionbetween the nuts willalter the vertical alignment of the pins, said pinsextending; toward and adapted to engage the pivoted member to index thetuning mechanism upon reciprocal movement of each rod and adjustable todifferent positionsby rotation ofeach rod, removable manually engageablemeans mounted on each rod end, lockingmeans to retain the rod in itsinnermost position when the manually engageable means is removed butinoperative to lock the rods when. the manually engageable means is inposition, means for manually rotatmg. the pivoted. member, clutch meansbetween the manual drive and the pivoted member and means actuated bythe reciprocating movement of any rod to disengage the clutch means.

a sacgaeo 8. In tuning mechanism, means for tuning a radio receiver,means for moving said tuning means to a plurality of predeterminedpositions, a plurality of reciprocable and rotatable members movabletoward said second-named means,

adjustable means threadedly mounted on the reciprocable means engageablewith the means for moving the tuning means to cause it to tune thereceiver when one of the members is recip- BERTRAM A. SCHWARZ. LUDWIG J..FICHTER.

